I think, too, that there is interest in upper class lives. Many archaeologists and historians have attempted to make working class lives interesting, but the records on that side are sparse, and even HBO's Rome--which produced decent working-class heroes--entwined those working-class heroes with the dramas of their "betters," in the personages of Julius Caesar and Mark Antony and Cleopatra.
However, the endless focus on the upper classes does get a trifle monotonous after awhile. Or, at least, it gets harder for the new novel to stand out from the rest, especially when the milieu seems entirely coincidental. Not there for plot reason. Just there so people can discuss wardrobes.
Consequently, I tend to prefer romances that take at least one step down the ladder. Loretta Chase's marvelous Dressmakers Series is a great solution to a reader's varied interests since she combines lords and dukes with extremely witty dialog and, most importantly, the sisters' desire to be the best dressmakers in London. They don't simply want to make money. They want to exercise their artistic abilities and managerial skills. The result is delightful books with strong denouements. (In fact, I wish the fourth book--Lady Clara's book, which focuses on legal cases rather than dressmaking--had concentrated more on the couple getting by in the equivalent of the middle class: not quite at Darcy's level, yet not as poor and struggling as Miss Bates.)Courtney Milan's Turner Series is somewhat darker than Chase's. However, it also manages to escape the "then they went to ANOTHER dance" scenes. Unraveled, for instance, deals with Smite Turner as a justice and the woman who becomes first his mistress and then his wife. Part of the book is focused on getting an a shipwright apprenticeship for a young man--not getting him into Eton. When Smite moves his mistress into a house, it is a townhouse: luxury for her but not, thank goodness, a mansion.
Moreover, though the Turner brothers have a family home and it is a nice place, scenes from the past indicate that at one point the cellar flooded. Even Darcy's cellar probably floods on occasion! (My Darcy-like father spent most of my childhood trying to figure out how to get rainwater not to drain into our basement: my childhood home was a ranch house on a hill.)
Without turning into a Marxist tract--because people in every age have survived and fallen in love, whatever their economic status (the micro life choices are considered more important than the macro theoretical meaning)--the book, set in Bristol, manages to capture a gritty reality in which people do exactly that.